Light source device and projector

A light source device comprising:

• a first light source configured to emit excitation light having a first wavelength band;
• a wavelength conversion member having a plurality of surfaces and configured to convert the excitation light made incident from the first light source into converted light having a second wavelength band different from the first wavelength band;
• and
• a first light transmissive member provided between the first light source and the wavelength conversion member and configured to transmit the excitation light, wherein
• the wavelength conversion member includes:
• a first surface on which the excitation light from the first light source is made incident;
• a second surface opposed to the first surface;
• and
• a third surface that emits the converted light,
• the first light transmissive member includes, on a surface opposed to the first surface of the wavelength conversion member, a first reflection layer that transmits the excitation light and reflects the converted light, and
• a gap is provided between the first surface and the first reflection layer.